engine overheating at over 40mph

[johnro79]

hello again


first time i've seen the coolant error. driving on M25 at 40-50 and when it cleared up i've tried to went up to 60.
then when light and warning came on: coolant too high ...
no major coolant usage, just maybe 300ml over 4years

i'm due for a timing belt and water pump anyway so i went on ETKA and tried my luck with part codes

WAUZZZ4G6EN078816
a6 c7 2.0 tdi 177 270k miles

this one got me confused (http://prnt.sc/ZnQ5jJDYD5E8): what's the difference between 03L121011J and 03L121011JX . i believe newer ones are 03L121011P and 03L121011PX
what is the X for ?

also, reading about faults and bulletins online, i've decided to replace the Thermostat too with a latest development one. is this the one i have to look for: 03L121111AD ?

my next confusion is with Bosch timing belt kits.
i've found 2 of them with different bosch part numbers (https://prnt.sc/pj23pVFUyr7O) but they bot fit (so they say).

how do i tell which is the right better one for my needs?


i'll try and run vcds today to see if there are any fault codes stored in regards to water pump/cooling
anyone could pls advise on which tests/reading should i perform in there to be able to test what parts might be wrong?

[dean warren]

Get a price on genuine stuff, J or JX or p or PX the ex can mean its an exchange item.


Sent from my iPad using Tapatalk

[johnro79]

Hi
Thanks for the input

Right now I'm trying to find the right part codes for my car.
I won't buy repairs or dodgy brands anyway :)

[VAG-Abound]

this one got me confused (http://prnt.sc/ZnQ5jJDYD5E8): what's the difference between 03L121011J and 03L121011JX . i believe newer ones are 03L121011P and 03L121011PX
what is the X for ?


The X usually denotes a rebult part - stripped, worn / wearable parts replaced, should be as good as new.

The P suffix seems to be listed as a later version for various non-Audi vehicles (where a J will also fit), while the Audi's stick with J. Sticking to something compatible with J may be best.



also, reading about faults and bulletins online, i've decided to replace the Thermostat too with a latest development one. is this the one i have to look for: 03L121111AD ?


That seems to be the right one. Can you read the part code on the existing one?



my next confusion is with Bosch timing belt kits.
i've found 2 of them with different bosch part numbers (https://prnt.sc/pj23pVFUyr7O) but they bot fit (so they say).

how do i tell which is the right better one for my needs?


One of them has a water pump, the other doesn't. Does that help you choose :)?

[johnro79]

One of them has a water pump, the other doesn't. Does that help you choose :)?

How did those get in there. I've must've printed the wrong items

Here's what I found from bosch , 2 full sets for the same car

[johnro79]

One of them has a water pump, the other doesn't. Does that help you choose :)?

How did those get in there. I've must've printed the wrong items

Here's what I found from bosch , 2 full sets for the same car

1987946974

1987946943

[dean warren]

Not sure how you got the above to show a quote from me though it isn’t anything i said…. Lol


Sent from my iPhone using Tapatalk

[johnro79]

Not sure how you got the above to show a quote from me though it isn’t anything i said…. Lol


Sent from my iPhone using Tapatalk

holly carp. sorry about that. gremlins-a-plenty today :)
between those 2 codes of mine, 1 was in stock , the other one wasn't . guess it made it easier (https://prnt.sc/YFqNPTZZ3I4v):)

[VAG-Abound]

Well I love a good bit of sleuthing, so as far as I can see...

From onlinecarparts.co.uk:


1 987 946 943 = 1 x Water Pump (Article №: 1 987 949 768) + 1 x Timing Belt Set (Article №: 1 987 946 582)
1 987 946 974 = 1 x Water Pump (Article №: 1 987 949 768) + 1 x Timing Belt Set (Article №: 1 987 946 384)


So the timing belt sets are different.

Looking at Bosch PDF guides for each:


https://media.partauto.fr/download/1987946582SI0000COB200.pdf
https://media.partauto.fr/download/1987946384SI0000COTR00.pdf


...there are new bolts for a few things in the first listed. That PDF (click the EN link at top left it comes up in German) might be a handy read as well :).

[johnro79]

Well I love a good bit of sleuthing, so as far as I can see...

From onlinecarparts.co.uk:


1 987 946 943 = 1 x Water Pump (Article №: 1 987 949 768) + 1 x Timing Belt Set (Article №: 1 987 946 582)
1 987 946 974 = 1 x Water Pump (Article №: 1 987 949 768) + 1 x Timing Belt Set (Article №: 1 987 946 384)


So the timing belt sets are different.

Looking at Bosch PDF guides for each:


https://media.partauto.fr/download/1987946582SI0000COB200.pdf
https://media.partauto.fr/download/1987946384SI0000COTR00.pdf


...there are new bolts for a few things in the first listed. That PDF (click the EN link at top left it comes up in German) might be a handy read as well :).

thanks a lot
from those pdf's, it seems that one kit has more pulleys/rollers then the other. otherwise , the belt and water pump seem to be the same

now back to step 1 for me. i've touched all hoses before and after the thermostat and they seem to have the same temperature, hot
is there anything i could do to check by using VCDS to diagnose if water pump/flow is my issue there?

i know, by being overdue i have to replace both timing belt and coolant pump. just wanna check if there might be smtg else wrong/bad that i could replace while doing that expensive work.

as a secondary concern, it it worth doing a coolant flush/clean since all this is being done?
never done this before and don't know what to use, how to flush/clean it properly and how much new coolant to have on hand afterwards

thanks a lot for all your help

[VAG-Abound]

I think the main thing to work out is why the engine was overheating. If you get the original water pump out and the impeller is damaged in some way that hopefully means the new pump will fix the core problem. If impeller parts are missing then you may need to think about which bits to flush which way to recover them. So for now I'd just focus on getting the pump out to see if it explains what was wrong.

You don't happen to have any kid of winter pack with extra warmers do you? No immediate problems come with that to mind - but it might help others think about which valves might be flaky.

[johnro79]

I think the main thing to work out is why the engine was overheating. If you get the original water pump out and the impeller is damaged in some way that hopefully means the new pump will fix the core problem. If impeller parts are missing then you may need to think about which bits to flush which way to recover them. So for now I'd just focus on getting the pump out to see if it explains what was wrong.

You don't happen to have any kid of winter pack with extra warmers do you? No immediate problems come with that to mind - but it might help others think about which valves might be flaky.

it's a plain black edition . no winter packs added. i have aux heater and heated seats though :)

after washing the car today, drove it for 7hrs. started early morning 5am till about 1pm.
went as fast as 55mph. nothing , no errors, no overheating, dial stayed at 90

as soon as the sun comes out, from 16degrees onward, my air con is playing up. starts blowing less and less cold air till it turns to warm (warmer then the outside temp)
stopped and moved the flow all 3 stages (lower/ front/windshield) : low is cold(ish)and front and windshield is warm air.
every time i turn the ac unit off and then on, it blows cold for a few sec and then it turns to warm
i've replaced the front radiator aircon pressure sensor yesterday

now , after reading about overheating coolant online, does audi has a safety cut thingy that blows hot air inside just to cool down the engine?
many managed to drive the car home when engine was overheated just by turning heat on full blast. is this smtg that comes as a safety feature rather then an indy trick?

also low oil pressure warning comes on quite often when the sun is out and car comes to a stand still . i have both sensors just don't know where they are to replace them. i've looked 2 hrs yesterday, can't see anything around the oil filter casing
can my oil pump be on the blink and trigger the overheating issues?

i remember 2 weeks ago, while doing 70mph, i've switched to manual mode and let it go for 30sec or so at about 2400rpm's. coolant temp went to 120 and after i've switched it back to auto and hence lowered the revs, after a min or two coolant went down to normal 90. no red warning though

i don't have an oil pressure gauge or the skills to use one. can i do anything in vcds to check idle values and driving ones too for coolant and oil.
i've done live measuring values for abs sensors but dont know which ones to chose for coolant and oil and also which are normal values to compare mine against

[Crasher]

Can you post a full VCDS scan?

[johnro79]

Can you post a full VCDS scan?

hi. there's nothing in there. empty
just my rooftop antenna with rusty connection


drove it ever since and done a motorway trip at 70mph. coolant was at 90 and aircon went down when outside was 18degrees+
i've topped up the coolant level with about 300ml though, so now it sits a little bit above the MAX level


£65 later, found out that my AC was just low on gas and needed a refill...